Compendium of dyadic intervention techniques (DITs) to change health behaviours: a systematic review

Background: Dyadic interventions for health behaviour change involving the romantic partner are promising. However, it often remains unclear how exactly the partner is involved in dyadic interventions. We propose a novel compendium of dyadic intervention techniques (DITs) that facilitates systematic description of dyadic interventions in terms of who performs what for whom during intervention delivery and subsequent implementation. Objective: We aimed to systematically characterise dyadic interventions along their degree of partner involvement and to provide a comprehensive list of DITs used in dyadic interventions with romantic partners. Methods: We systematically reviewed dyadic health behaviour change interventions with controlled designs. We included 165 studies describing 122 distinct dyadic interventions with romantic partners. Interventions were classified along their degree of partner involvement, 160 DITs were extracted, and their frequencies of use counted. Results: The majority of interventions (n = 90, 74%) explicitly instructed partners to interact. Half of the DITs were performed jointly by the couple and also targeted the couple. Mostly, couples were instructed to jointly practice communication skills and to jointly perform problem solving for the couple. Discussion: The present review contributes to the development of a shared and systematic way of describing dyadic interventions to facilitate cumulation of evidence.